Simultaneous depth-resolved imaging of sub-nanometer scale ossicular vibrations and morphological features of the human-cadaver middle ear with spectral-domain phase-sensitive optical coherence tomography

We describe a novel method for the detection of the tiny motions of the middle ear (ME) ossicles and their morphological features with a spectral-domain phase sensitive optical coherence tomography (PS-OCT). Laser Doppler Vibrometry (LDV) and its variations are the most extensively used methods for studding the vibrational modes of the ME. However, most techniques are limited to single point analysis methods, and do not have the ability to provide depth resolved simultaneous imaging of multiple points on the ossicles especially with the intact eardrum. Consequently, the methods have the limited ability to provide relative vibration information at these points. In this study, we demonstrated the feasibility of using PS-OCT for simultaneous depth resolved imaging of both vibration information and morphological features in a cadaver human middle ear with high sensitivity and resolution. This technique has the potential to provide meaningful vibration of ossicles with a vibration sensitivity of ~0.5nm at 1kHz acoustic stimulation. To the best of our knowledge, this is the first demonstration of depthresolved vibration imaging of ossicles with a PS-OCT system at sub-nanometer scale.